1. Field of the Invention
The present invention relates to a method of controlling a disc drive, and more particularly, to a method of detecting a crack on a disc loaded on a disc drive and a method of automatically lowering a target speed in response to the detection of a crack in order to stabilize the disc drive.
2. Description of the Related Art
Optical disc recording media include compact discs such as CD-ROMs and digital versatile discs or DVDs suitable for multimedia. Disc drives corresponding to these optical disc recording media read data by radiating a laser beam at a track on a turning disc using an optical pickup and detecting light reflected from the track, or record data by radiating a laser beam which is recording data after having been modulated.
To increase the data processing speed of such a disc drive, the system has been improved to increase the speed of rotation of a disc. The speed factor of present disc drives has rapidly increased to forty-eight times a single speed disc drive (48×) or more. As the speed of a disc drive is increased, a probability that an error occurs during data recording or reproduction increases when a disc has a defect. In particular, when a disc having a crack is rotated at a high speed, the disc can be eventually broken. This may fatally damage the disc drive and, moreover, threatens the safety of users.
A conventional disc drive cannot detect a crack on a disc and rotates a disc at a maximum speed set regardless of existence/nonexistence of a crack. Accordingly, the disc drive can be fatally damaged. Moreover, the safety of users may be threatened.